This invention has to do with the ground handling of light aircraft, whereby a person can maneuver an aircraft over pavement or ground terrain and their normal obstructions. Ground handling of light aircraft by a pilot, or any single person, is quite necessary in order to move the plane without operating its engine. For example, the aircraft might be moved about a parking area or within a hanger space, or for the purpose of servicing. There is a wide variety of landing gear configurations, the most common of which is the tricycle landing gear having right and left main struts and a fowardly placed and centered nose strut. The main struts are equiped with larger diameter wheels, while the nose strut is equiped with a smaller diameter wheel, and all of which are fitted with pneumatic tires. And, the main gear wheels are disposed on fixed transverse axes, while the nose wheel is steerable on a centered axis. It is a general object of this invention to provide a towbar come-along combination to enable a single person to maneuver light aircraft over pavement or ground terrain and their normal obstructions. That is, to enable the person to move the aircraft over rises and out of depressions, including chuckholes, rocks, pipes or hoses, etc..
Heretofore, simple towbars have been provided for attachment to the wheels of aircraft, whereby the craft can be pulled or pushed by a person. And, for larger aircraft such devices have been motorized with either ground engaging drive wheels or with tire engaging drive rollers. The simple towbar is often inadequate and the motorized devices are too expensive and too cumbersome. And, in light aircraft there is no room or weight permissibility to carry cumbersome and heavy equipment. Accordingly, it is an object of this invention to provide a light and portable towbar come-along that can be conveniently carried aboard light aircraft.
Prior art motorized towing machines drive the aircraft nose wheel by means of a drive roller engaging the tire, and with a handle extended for steering. Such machines have been provided with motors or engines, to apply torque to the nose wheel. It is an object of this invention to apply torque to an aircraft wheel without the use of motors or engines, by means of a lever system wherely the towbar is a come-along having leverage to apply torque to said aircraft nose wheel and/or tire.
The towbar lends itself to use as a lever, it being an object of this invention to implement this potential by providing ratchet means to torque the aircraft wheel, preferably the nose wheel, either directly or indirectly.
In FIGS. 10 and 11 the ratchet means is a lever combination that diretly torques the nose wheel.
In FIGS. 1 through 9, the preferred form, the ratchet means is a lever in combination with an over-riding roller that indirectly torques the nose wheel. In either form the nose wheel is torqued by a lever system involving the towbar.
It is an object of this invention to provide ratchet positioning means by which the ratchet means is put into pressured engagement with the nose wheel tire in order to torque the same. In the FIG. 10 and 11 embodiment this pressure is applied through a second class lever, as will be described. In the FIG. 1 through 9 embodiment this pressure is applied through a toggle means, as will be described.
It is another object of this invention to provide adjustability so as to accomodate different diameter wheels and variations in tire inflation. In the FIG. 10 and 11 embodiment there are adjustment holes for selective positioning of the second class lever fulcrum. In the FIG. 1 through 9 embodiment there is a screw adjustment to position the toggle means that depresses the over-riding roller into the tire.
It is still another object of this invention to provide reversibility of torque application to the aircraft wheel and/or tire. In the FIG. 10 and 11 embodiment the towbar come-along unit is simply turned over; being shown in a forward drive position in the drawings. In the FIG. 1 through 9 embodiment the handle lever is rotated 180.degree. (see FIGS. 5 and 8); being shown in a forward drive position throughout the drawings.
A feature of this invention is the rigidity of the lever system and its application and removability to the nose wheel of the aircraft. Aircraft axles vary in design, most of which are tubular as shown herein. However, some aircraft axles present closed ends with nuts, for example, in which case adaptation thereto is by means of sockets rather by the trunions shown herein. The attachment portion of the lever as shown herein is of fork configuration, at least one leg of which is moveable as shown in the FIG. 1 through 9 embodiment, and both of which are flexible in the FIG. 10 and 11 embodiment.
Still another object of this invention is the provision of a nose wheel chock in combination with the towbar come-along, whereby movement in the opposite direction of travel, forward or backward, is precluded.